Form tool generating fixture



Dec. 17, 1946. A w E oss FORM TOOL GENERATING FIXTURE Filed Nov. 4, 1944 5 Sheets-Sheet l Dec. 17, 1946. w. F. ROSS FORM TOOL GENERATING FIXTURE 5 Sheets-Sheet 2 Filed Nov. 4, 1944 m 7 INVENTOR.

Dec. 17, 1946. w E oss 2,412,653

FORM-TOOL GENERATING FIXTURE Filed Nov. 4, 1944 5 Sheets-Sheet 3 IN V EN TOR.

Patented Dec. 17, 1946 FORM TGOL GENERATING FIXTURE Walter F. Ross, Oakland County, Mich, assignor to Motor Tool Manufacturing Company, Detroit, Mich, a corporation of Michigan I Application November 4, 1944, Serial No. 561,988

12 Claims.

This invention relates to circular form tool grinding fixtures and has for its object to provide an arrangement in which the grinding of such form tools of complicated outline, and more especially of outline having abrupt variations in form, may be effected by the operator to conform with conditions imposed by the form of a master dummy with great facility and accuracy.

An important object of the said invention is to provide such a device in which a follower finger traverses the dummy and thereby limits the variable relationship of the work to the abrasive wheel, to secure the ground reproduction of the contour of the dummy on the work, and in which this relationship may be accurately and readily preserved throughout changes which may be made in the angularity of presentation of the abrasive wheel to the work such as may be necessary to the operator in the grinding of shoulders. steps, sharply bevelled outlines, and so forth.

More articularly it is an object of the said invention to provide for the coupled angular manual adjustment of the abrasive wheel and the follower finger whereby their points of contact with the work and with a master dummy, respectively, will be maintained in the same relation to the respective centers of angular adjust-v ment of the said follower finger and the abrasive wheel support.

Afurther object is to'provide for the adjust.- ment of the abrasivewheel upon its reduction in diameter, a by dressing, to bring the arc of swinging ofthat portion of the periphery of the wheel presented to the work into radial conformity with the arc of swinging of the follower finger.

A still further object of the said invention is to provide for control of a work-carrying table in such manner that the work may be either manually fed toward the abrasive wheel, subject to limitations imposed by the master dummy, or allowed to automatically move with respect to the abrasiv wheel under such influence and under the further influence of a Weight or similar means biasingthe work table in the direc.- tion of the abrasive wheel. 1

Still further objects or advantages additional or subsidiary to the aforesaid objects, or resulting from the construction or operation of the invention as it may be carried into effect, will become apparent as the said invention is hereinafter further disclosed.

In carrying the invention into effect. 1 mayv adopt the. novel construction and arrangement.

. 2 of art hereinafter describedbyway of example, having reference to the accompanying drawings, wherein:

Figure 1 is a side elevation, shown partly in section, of a grinding machine embodying the said invention;

Figur 2 is a plan view of the same; and Figure 3 is a similar view to Figure 2 illustrating a different operational position of the parts.

Similar characters of reference indicate similar 1 parts in the several figures of the drawings. 7

i 6 indicates the fixed base structure of a grinding machine supporting a work table I! which is subject to controlled longitudinal feed by mechis common to such pinge against a stop I? on the end of the said feed screw it: whereby the operation of the said ieed screw may b effective in controlling adjustment of the said table but, at the same time, permitting the said. table to be freely moved without interference of the saidfeed screw in a direction to positions forward of the saidstop.

The said work table i3 is hollow or has suitable spacing provided on its under side to accommodate linkage mechanism, as will be explained,

and also has a suitable opening in the top thereof to provide clearance for the movement of a finger post I2 operated by the said linkage mechanism.

Mounted on either end portions of the said transversely slidable table I3 are tail stocks l8 and i9, hereinafter referred to as the'left hand and right hand tail stocks, respectively, the left hand tail stock carrying two centers 20 and 2| in parallel horizontally spaced relation to each other, and the right hand tail stock 19 similarly carrying two centers 22 and 23 inaxial alignment with the said centers Zlland 2|. The tail stocks is and iii are adjustable toward and from one another on the said table I 3 to accommodate work or arbors of varying lengths. In the present example an arbor 24 is shown as carried between the centers 28 and 22 and an arbor 25'between the centers 2 and 23, the arbor 24 having a pulley 25 mounted thereon which is coupled. by the belt 3 27 with the pulley 28 of a motor 29 carried on the tail stock l9.

The arbor 35 has mounted thereon a dummy 36 having the profile of the Work to be ground, which profile in this instance is characterized by a central portion 31 of conventionally cylindrical form, terminating at one end in a 90 shoulder 38 and at the other end in a bevelled shoulder 39, the enlarged end portions of the dummy 36 having concaved cylindrical surfaces 40 and 4|. These various forms of profile are to be ground on work, such as a rotary form cutter 42, mounted on the arbor 24 and present a grinding problem which the present invention and the mechanism described herein solves in a simple and highly efficient manner. For the sake of clear illustration and simplicity the solid outline of the work is shown without illustrating the presence of teeth or grooves which are characteristic of a rotary cutter and which may be of various forms.

43 is a follower finger carried by the upper end of the finger post l2 to engage the surface of the said dummy 36 for the purpose of causing the transversely slidable table I 3 to move laterally under the influence of the weighted lever M in conformity with the outline of the said dummy over which the said follower finger 43 passes as the table H is fed longitudinally. It is not intended that the dummy '36 rotate during such operation although it may be rotated from time to time as by hand between operations to provide a new wearing surface for contact with the finger 43, if thought necessary or desirable. The work, however. is rotated through the agency of the motor 29 during such movements of the table in order that a suitable grinding wheel, such as 44, may effect the circular grinding of the work in conformity with the profile determined by the cooperative action of the follower finger 43 and the dummy 36.

It will be observed that, in the example, the stop I! of the feed screw is capable of being moved to a spaced position from the abutment 16 of the table ll so that the said table may be free to move laterally under the influence of the weighted lever l4 to an extent limited by the contact of the dummy 36 with the follower finger 43. Thus, with the table so freely movable, such outlines as the concaved cylindrical surfaces 40 and 4! of the dummy may be ground in reproduction on the work 42 by the abrasive wheel 44 by simply permitting the said table II to adjust itself laterally under the influence of the progression over the said profiled surfaces 40 and 4| of the said dummy of the point of the follower finger 43, when required longitudinal movement is imparted to the said table by the regularly provided longitudinal feed mechanism common to grinding machines.

It will be readily understood that this generation of the said profiled form on the work is due to the fact that the motions of the dummy travelling over the follower finger are imparted, through the corresponding motions of the table II, to the work 42 carried in parallel with the said dummy by the said table l I.

In many form tools of complicated outline it is frequently impossible to have the follower finger define such outline in a continuous manner Or with an abrasive wheel dressed to only one peripheral form. For instance, in the exampleshown, the 90 shoulder 38 could not be ground with the radially dressed wheel 44 as shown in Figure 2, neither does the bevelled shoulder 39 offer itself to being properly reproduced by such a wheel. Moreover, neither of these shoulders, and especially the first, lend themselves to a continuous generating motion of the dummy over the finger 43 as will be obvious, and, in cases such as these, I propose by hand adjustment of the feed screw [5 to bring the feed screw stop 11 into controlling contact with the abutment l6 of the table I l whereby required movement of the dummy 36 in relation to the follower finger 43 may be effected manually by operation of the said feed screw I5.

It is also desirable, in eifecting the grinding of such shoulders as 38 and 39, that a follower finger such as 45 of suitably modified form be substituted for the finger 43 and be presented at an angle to the shoulder to conform with the angle at which a correspondingly substituted abrasive wheel 46 is presented to the work, as shown in Figure 3. To enable this to be done without disturbing the working relationship as to position of motion between the dummy and its follower finger, and between the work and the grinding wheel, I provide means for coupling the grinding Wheel and the follower finger together for co-related angular adjustment so that the point of the follower finger during such adjustment will traverse the same are and degree as does the active grinding point of the abrasive wheel.

To accomplish this in a simple manner, I may mount the spindle 41 of the abrasive wheel on a tum-table 48 mounted on a suitable pedestal 49. This pedestal is shown as being provided with a stationary clamp bracket 50 extending forwardly beneath the table I l to support a pivot 5! on which a finger swivel bracket 52 is mounted. This bracket carries the finger post l2, previously referred to, and also has connected thereto, in spaced relation to and on opposite sides of the said pivot 5|, links 53 and 54, the rear ends of which links are connected at 5-5 and 56 to the under side of the said turntable 48.

As a result of this linkage any angular adjustment of the grinding wheel, by rotation of the turn-table 48, will be accompanied by corresponding angular adjustment of the finger swivel bracket '52 as will be clearly observed by a comparison of Figures 2 and 3. When such an adjustment is made, as for the purpose of grinding the form of the shoulder 38 on the work, the table II is moved longitudinally and laterally to bring the said shoulder 38 into contact with the follower finger 45 which will bring the work into correct position with respect to the abrasive wheel for the grindin of such a shoulder on the said work; and the required motions of the work relative to the abrasive wheel, for effecting such operation, may then be readily and accurately instituted by the manual longitudinal and lateral adjusting of the said table II by feed means provided and to the extent required.

As far as the grinding of the form of the shoulder 39 on the work is concerned, the following of the contour may be effected by hand control of the table where the angle of the shoulder is so steep as to render this necessary or desirable; but where the angle is such that it does not preclude it, the feed screw stop I 1 may be released from the feed table abutment IE to permit the follower finger to freely ride the angular surface and thereby directly and. solely H during its longitudinal movement relative to the said follower finger.

5'! indicates a suitable type of wheel dresser whichmay be interchangeable from one type to another according tothe form to be dressed on the abrasive wheel and 58 is a micrometer screw for moving the dresser into the wheel as required.

In order to maintain the working point on the wheel at a determined distance from the center of rotation of the turn-table 48 so that its arc of swinging adjustment will conform with that of the finger, the abrasive wheel after dressing should be moved up to the work to an extent equal to the amount dressed of the periphery of the wheel. For such purpose it may be considered that the support 59 on which the abrasive wheel assembly is mounted is slidable to some extent as in dove tail ways so formed on the table 48 under'the influence of the micrometer adjusting screw 6|.

Thus if the dresser adjusting screw 58 be advanced, say, .005 in dressing the abrasive wheel the wheel adjusting screw SI is thereafter accordingly advanced .005" to compensate for the reduction of the grinding wheel radius, as will be well understood. As there is a limit to the extent to which it may be practical to move up the abrasive wheel in the manner described, it maybe necessary to discard the grinding wheel when its radius has been reduced to such limitation and a new wheel substituted therefor after retraction of the wheel support 59 to its original centralized position on the turn-table 43.

With an arrangement such as that described rapid and accurate reproduction of complicated forms on a form tool cutter from a master dummy may be effected with great facility.

This invention may be developed Within the scope of the following claims without departing from the essential features of the said invention, and it is desired that the specification and drawing be read as being merely illustrative of a practical'embodiment of the said invention and not in a strictly limiting sense.

What I claim is:

1. In a circular form tool grinding device of the class described, a work-guiding table, a workgrinding abrasive wheel, a profiled stop carried by said table havin the form of the envelope of the work as it is to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, means for adjusting the angularity of presentation of the said wheel and the said follower to the work and to a dummy respectively, and means for adjustably moving said wheel toward the work perpendicular to the axis of the Wheel, while maintaining the relationship of the axis of angular setting of the wheel to the angular setting axis of the follower.

2. In a circular form tool grinding device of the class described, a work-guiding table, a workgrinding abrasive wheel, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, means coupling said wheel to said follower for coordinated angular adjustment relative to the work and to said profiled stop, respectively, and means for adjustably moving said wheel toward the work perpendicular to the axis of the wheel, while maintaining the relationship of the axis of angular setting of the wheel to the angular setting axis of the follower.

3. In a circular form tool grinding device of the class described, a work-guiding table, a turntable, awork-grinding abrasive wheel mounted on said turn-table for angular adjustment to the work, a profiled stop carried by said table having the form of the envelope of the work 'as it is to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, a finger swivel bracket coupled to said turntable whereby angular adjustment of both said wheel and said follower finger may be ccordinated, adjustable means for synchronizing the radial swinging arc of the working contact point of said wheel with the radial swinging arc of thecontact point of said finger, and means for adjustably moving said wheel toward the work perpendicular to the axis of the wheel, while maintaining the relationship of the axis of angular setting of the wheel to the angular setting axis of the follower.

4. In a circular form tool grinding device of the class described, a work-guiding table, a Workgrinding abrasive wheel, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a normally stationaryfollower finger presented to a longitudinal line on the profiled surface of said stop, means for adjusting the angularity of presentation of the said wheel and the said follower to the work and to said profiled stop, respectively, for the purposes specified, releasable manual means for feeding said work-table toward said wheel, and means biasing said table in the direction of said wheel when said manual feed is released.

5. Ina circular form tool grinding device of the class described, a work-guiding table, a workgrinding abrasive Wheel, a profiled stop carried by said table having the form of the envelope of the work as it is to ground, a normally stationary follower finger presented to a longitudinal line on the profiled surface of said stop, means coupling said wheel to said follower for coordinated angular adjustment relative to the work and to said profiled stop, respectively for the purposes specified, releasable, manual means for feeding said work-table toward said wheel, and means biasing said table in the direction of said wheel when said manual feed is released.

' 6. In a circular form tool grinding device of the class described, a work-guiding table, a turntable, a work grinding abrasive wheel mounted on said turn-table for angular adjustment to the work, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a normally stationary follower finger presented to a longitudinal line on the profiled surface of said stop, a finger swivel bracket coupled to said turn-table whereby angular adjustment of both said wheel and said follower finger may be coordinated, for the purposes specified, releasable manual means for feeding said work-table toward said wheel, and means biasing said table in the direction of'said wheel when said manual feed is released.

7. In a circular form tool grinding device of the class described, a work-guiding table, a Workgi-inding abrasive wheel, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, means for adjusting the angularity of presentation of the said wheel and the said follower to the work and to said profiled stop, respectively, adjustable means for synchronizing the radial swinging arc of the working contact point of said wheel with the radial swinging arc of the contact point of said finger, re.- leasable means for feeding said work-table toward said wheel, and means biasing said table in the direction of said wheel when said manual feed is released.

8. In a circular form tool grinding device of the class described, a work-guiding table, a workgrinding abrasive wheel, a profiled stop carried by said table having the form of the envelope of the work as it i to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, means coupling said wheel to said follower for coordinated angular adjustment relative to the work and to said profiled stop, respectively, adjustable means for synchronizing the radial, swinging arc of the working contact point of said wheel with the radial swinging arc of the contact point of said finger, releasable manual means for feeding said work-table toward said wheel, and means biasing said table in the direction of said wheel when said manual feed is released.

9. In a circular form tool grinding device of the class described, a work-guiding table, a turntable, a work-grinding abrasive wheel mounted on said turn-table for angular adjustment to the work, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, a finger swivel bracket coupled to said turntable whereby angular adjustment of both said wheel and said follower finger may be coordinated, adjustable means for synchronizing the radial swinging arc of the working contact point of said wheel with the radial swinging arc of the contact-point of said finger, releasable manual means for feeding said work-table toward said wheel, and means biasing said table in the direction of said wheel when said manual feed is released.

10. In a circular form tool grinding device of the class described, a work-guiding table, a workgrinding abrasive wheel, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, means for adjusting the an- 11. In a circular form tool grinding device of the class described, a work-guiding table, a workgrinding abrasive wheel, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a follower finger presented to a longitudinal line On the Profiled surface of said stop, means coupling said wheel to said follower for coordinated angular adjustment relative to the work and to said profiled stop, respectively, means for adjustably moving said wheel toward the work along the plane of its presentation to the work, releasable manual means for feeding said work-table toward said wheel, and means biasing said table in the direction of said wheel when said manual feed is released.

12. In a circular form tool grinding device of the class described, a work-guiding table, a turntable, a work-grinding abrasive wheel mounted on said turn-table for angular adjustment to the work, a profiled stop carried by said table having the form of the envelope of the work as it is to be ground, a follower finger presented to a longitudinal line on the profiled surface of said stop, a finger swivel bracket coupled to said turn-table whereby angular adjustment of both said wheel and said follower finger may be coordinated, adjustable means for synchronizing the radial swinging arc of the working contact point of said wheel with the radial swinging arc of the contact point of said finger, means for adjustably moving said wheel toward the work along the plane of its presentation to the work, releasable manual means for feeding said work-table toward saidwheel, and means biasing said table in the direction of said wheel when said manual feed is released.

WALTER F. ROSS. 

